This invention relates to a method for verifying data of a lithographic apparatus and a method for manufacturing a photo mask, particularly suitable for use in verification of conversion results of data for a lithographic apparatus used for manufacturing a photo mask.
LSI patterns are increasing in micro-miniaturization and in complexity. Accordingly, data for electron beam lithographic apparatuses made from LSI pattern data are increasing in volume and complexity.
Therefore, verification that a plurality of electron beam lithographic data coincide for the purpose of ensuring accuracy of acquired electron beam lithographic data is generally conducted after making a plurality of electron beam lithographic data from an LSI pattern in a converter apparatus having functions of logical operation and size processing of objects, or in a plurality of data conversion processing systems like conversion software.
The electron beam lithographic data, in general, are composed of data of rectangular objects 101, 102, 103 and trapezoidal objects 104, 105 as shown in FIG. 6A. However, in data made by a different data conversion processing system, the same data are made up of rectangular objects 101, 102 and triangular objects 106, 107 as shown in FIG. 6B. That is, there might be a difference in the way of dividing an object. Therefore, the aforementioned verification process also employs a process of confirming whether any difference exists or not by conducting graphic exclusive logic sum in a converter apparatus having functions of logical operation and size processing of objects, or in data conversion processing systems like conversion software.
Since graphic logical operation is conducted also for verifying whether two electron beam lithographic data are of the same pattern or not as explained above, it needs an enormous length of processing time as the verification time in addition to the usual conversion time. As a result, it has been a problem that a very long time was required for making electron beam lithographic data and its turn-around-time (TAT) increased.
It is therefore an object of the invention to provide a method for verifying lithographic data and a method for manufacturing a photo mask, which can greatly reduce the verification time to thereby reduce the turn-around-time in preparation of lithographic data and can efficiently manufacture photo masks.
According to the first aspect of the invention, there is provided a method for verifying lithographic data for a lithographic device, characterized in:
comparing a plurality of lithographic data on the basis of data formats thereof; and
according to the result of comparison based on the data formats, extracting data from individual lithographic data of the plurality of lithographic data excluding data common to all of the lithographic data as difference data corresponding to individual lithographic data, and graphically comparing respective difference data to conduct verification.
According to the second aspect of the invention, there is provided a method for verifying data for a lithographic device, characterized in:
comparing a first lithographic data and a second lithographic data on the basis of data formats thereof; and
according to the result of comparison based on the data formats, extracting data from the first lithographic data in the data format excluding data common to the second lithographic data as a first difference data, and extracting data from the second lithographic data in the data format excluding data common to the first lithographic data as a second difference data, to graphically compare the first difference data and the second difference data to conduct verification.
According to the third aspect of the invention, there is provided a method for manufacturing a photo mask, which makes a photo mask on the basis of lithographic data for a lithographic device, comprising:
comparing a plurality of the lithographic data on the basis of data formats thereof; and
according to the result of comparison based on the data formats, extracting data from individual lithographic data of the plurality of lithographic data excluding data common to all of the lithographic data as difference data corresponding to individual lithographic data, and graphically comparing respective difference data to conduct verification.
According to the fourth aspect of the invention, there is provided a method for manufacturing a photo mask, which makes a photo mask on the basis of lithographic data for a lithographic device, comprising:
comparing a first lithographic data and a second lithographic data on the basis of data formats thereof; and
according to the result of comparison based on the data formats, extracting data from the first lithographic data in the data format excluding data common to the second lithographic data as a first difference data, and extracting data from the second lithographic data in the data format excluding data common to the first lithographic data as a second difference data, to graphically compare the first difference data and the second difference data to conduct verification.
In the first and third aspects of the invention, verification is typically the verification of whether a plurality of lithographic data are graphically identical data or not.
In the second and fourth aspects of the invention, verification is typically the verification of whether a first lithographic data and a second lithographic data are graphically identical data or not.
In the second and fourth aspects of the invention, verification is preferably conducted by graphically comparing a first difference data and a second difference data, thereby extracting the part not common to the first and second difference data as a third difference data, and verifying whether the third difference data contains any data. In the case where the second lithographic data is corrected one of the first lithographic data obtained by operation processing of the first lithographic data, a fourth difference data is made by operating the third difference data by the opposite operation processing from that of the first lithographic data after extracting the third difference data. Then, it is verified whether the fourth difference data contains any data or not. If the fourth difference data contains any data, correction of the first lithographic data is judged to be abnormal. If it does not contain any data, correction of the first lithographic data is judged to be normal.
In the second and fourth aspects of the invention, for the purpose of minimizing the time required for verifying whether the first lithographic data and the second lithographic data are identical or not, preferably when the first difference data and the second difference data contain no data, the first lithographic data and the second lithographic data are judged to be graphically identical.
In the second and fourth aspects of the invention, for the purpose of minimizing the time required for verifying whether the first lithographic data and the second lithographic data are identical or not, preferably when the first difference data contains data whereas the second difference data contains no data, the first lithographic data is determined to be different in the first difference data.
In the second and fourth aspects of the invention, for the purpose of minimizing the time required for verifying whether the first lithographic data and the second lithographic data are identical or not, preferably when the second difference data contains data whereas the first difference data contains no data, the second lithographic data is determined to be different in the second difference data.
In the second and fourth aspects of the invention, preferably when the third difference data contains no data, the first lithographic data and the second lithographic data are determined to be graphically identical, and when the third difference data contains any data, the first lithographic data and the second lithographic data are determined to be graphically different in the third difference data.
According to the lithographic data verification method and the photo mask manufacturing method having the above-summarized structure proposed by the present invention, by comparing a plurality of lithographic data with reference to a data format, thereby extracting from each lithographic data the part excluding that common to all of the lithographic data as a difference data in each lithographic data, and then comparing and verifying respective difference data, it is possible to limit graphic operation processing to the only lithographic data different in the data format and thereby largely reduce the amount of data to be graphically operated.